Field of the Invention
The present invention relates to an image forming system including a punching unit having a punch die removably mounted thereon for forming punched holes in a sheet.
Description of the Related Art
Conventionally, there has been known an image forming apparatus including a post-processing apparatus for forming punched holes in a sheet (see U.S. Pat. No. 7,627,282).
U.S. Pat. No. 7,627,282 proposes an image forming system including a punching device (puncher) as a post-processing apparatus for forming punched holes in the leading end, as viewed in a sheet conveying direction, of a sheet discharged from an image forming apparatus.
Such a puncher as mentioned above has a structure configured such that a desired one of a plurality of punch dies different e.g. in the shape or the number of punch holes can be selectively mounted thereon.
Incidentally, in order to maintain the durability of a punch die which is mounted in a puncher, it is preferable to perform periodical lubrication, and it is required to perform proper management of lubrication timing.
For this reason, conventionally, a puncher which has a punch die mounted thereon is provided with a counter for managing punch dies on a die type-by-die type basis, and timing for lubrication of each punch die or exchange of punch dies is managed based on the count of the counter.
For a puncher in which a punch die can be exchangeably mounted, so as to properly manage the timing for lubrication of each punch die or exchange of punch dies, there is envisaged a method of mounting a nonvolatile memory on each of the punch dies, and storing lubrication information in each of the nonvolatile memories, for management.
However, to update the lubrication information stored in the nonvolatile memory (punch die memory) mounted on a punch die, it is necessary to mount the punch die in a puncher. On the other hand, lubrication work is performed in a state where the punch die is removed from the puncher.
More specifically, to update lubrication information stored in a punch die memory, a process is required in which, first, the punch die is mounted in the puncher so as to check the lubrication information, then the punch die is removed from the puncher for execution of lubrication work, and thereafter the punch die is mounted in the puncher again for update of the lubrication information.
As a consequence, work for managing memory information becomes complicated, and work time becomes long. Further, in a case where the same punch die is mounted in a plurality of punchers for use among them, there is a problem of occurrence of a situation in which it is impossible to properly manage lubrication information including the count of a counter and lubrication execution timing.